Efeito de um inibidor de metaloproteinases de matriz MMPs na estabilidade da adesão entre sistemas adesivos e a dentina humana

• Autor(a) principal: Brandão, Natasha Lamêgo
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal Fluminense (RIUFF)
• Texto Completo: https://app.uff.br/riuff/handle/1/20775
• topic: Dentina; Adesivos Dentinários; Clorexidina; Dentin; Dentin-Bonding Agents; Chlorhexidine; CNPQ::CIENCIAS DA SAUDE

This study aimed at evaluating the effectiveness of a matrix metalloproteinases (MMPs) inhibitor on the stability of the bonding between adhesive systems and human dentin, presenting laser confocal microscopy (LCM) as a new method for topographic analysis of bonding interfaces. Twenty-four molars had their occlusal enamel removed and the dentin surfaces polished with silicon sandpaper 600 to standardize the smear layer. Two adhesive systems were used: Adper Single Bond 2 SB2 (etch and rinsing) and Clearfil SE Bond CSE (self-etching). Four groups were produced (n= 6): C (control): adhesives were applied according to manufacturer s instructions; and Cx: after etch and rinse (SB2) or the application of the self-etching primer (CSE), the surfaces were treated with 2% chlorhexidine digluconate. A block of composite with 5 mm in height was built up on dentin surfaces and the teeth were sectioned in two axis to obtain composite-dentin sticks with ≈ 0.8 mm2 of cross section. The adhesive systems and the resin composite were photoactivated using a irradiance of 650 mW/cm² (Optilux 501, Demetron Inc., Danburry, USA), checked by a radiometer (Model 100, Demetron Inc., Danburry, USA). Those sticks were stored in distilled water at 37°C and subjected to microtensile bond strength test - TBS - (half after 24h and half after 6 months). The failure mode was evaluated in a stereomicroscope and under a LCM. The TBS data were subjected to three-way ANOVA (adhesive system x application protocol of aqueous solution of chlorhexidine digluconate x storage period) and Tukey HSD test ( = 5%). The failure types were evaluated by percentage. For both groups (C and Cx), SB2 showed no significant reduction in TBS after 6 months of storage. On the contrary, in group C, CSE showed a statistically significant reduction of TBS after 6 months of storage. Moreover, in the group treated with Cx, the CSE showed similar result to SB2, that is, no decrease in TBS after 6 months of storage. In relation of the bonding failure type, with exception of CSE adhesive system from Cx group, where was observed 54,55% of adhesive failures after 24h of storage and 76% after 6 months of storage, in the remaining groups the mixed failures were predominant. Excepting CSE adhesive system applied on Cx treated dentin surfaces, all the other groups presented a percentage increase of cohesive failures after 6 months of storage. The LCM topographic analysis allowed the observation of structures like hackles marks and Wallner lines. Therefore, the application of 2% chlorhexidine digluconate was able to maintain the stability of bond strength after 6 months of storage in distilled water.